Answer:
Microscopes and telescopes often use two lenses to make an image large enough to see. A compound microscope uses two lenses to achieve high magnification. Both lenses are convex, or converging. Light from the object first passes through the objective lens.
Explanation:
A compound microscope uses two lenses to achieve high magnification
Potassium nitrate, bKNO3 , is 38.7% potassium by mass. If you have 300 grams of KNO; how many grams of potassium can you extract from it?
Mass of Potassium : 116.1 g
Further explanationGiven
38.7% potassium in Potassium nitrate
300 g of KNO3
Required
mass of potassium
Solution
%mass of element = (mass of an element in 1 mole of compound/mass of 1 mole compound) x 100%
mass of K(potassium) in 300 g KNO3 :
= 38.7% x 300 g
= 116.1 g
Hurry I need Now!!!In which biome would the climax species be reached most quickly following a fire?
A Taiga
B desert
C Grassland
D. deciduous forest
E tropical rain forest
Answer:
D. Deciduous Forest.
Explanation:
Determine whether the given name for each ionic compound is correct or not. C o I 2 CoIX2: cobalt(II) iodide Correct name B a C l 2 BaClX2: barium dichloride Correct name C s 2 O CsX2O: cesium oxide Choose... R b 2 S RbX2S: rubidium sulfite Correct name S r B r 2 SrBrX2: strontium(II) bromide Incorrect name
Answer: [tex]CoI_2[/tex] : cobalt (II) iodide : correct
[tex]BaCl_2[/tex] : barium di chloride : incorrect
[tex]Cs_2O[/tex] : cesium oxide: correct
[tex]Rb_2S[/tex] : rubidium sulphite : incorrect
[tex]SrBr_2[/tex] : strontium (II) bromide : correct
Explanation:
The nomenclature of ionic compounds is given by:
1. Positive is written first followed by the oxidation state of metal in roman numerals in parenthesis.
2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.
Hence, the name of [tex]CoI_2[/tex] is cobalt (II) iodide, [tex]BaCl_2[/tex] is barium (II) chloride, [tex]Cs_2O[/tex] is cesium oxide, [tex]Rb_2S[/tex] is rubidium sulphide and [tex]SrBr_2[/tex] is strontium (II) bromide.
How many moles are in 3.69 x 1022 atoms of Ag?
Answer:
I'm assuming that 1022 is supposed to be 10^22, or 10 to the 22nd power. If that is the case, then the answer is 0.0612956811 mol. Round it to the number that you are supposed to round it to.
If H3O+ is an acid according to Brønsted-Lowry, what is its conjugate base?
Select one:
Need ASAP please
a. H4O2+(aq)
b. H+(aq)
c. H2O(aq)
d. OH-(aq)
Answer:
C. H20(aq)
Explanation:
compute the mass-specific enthalpy change associated with Nz that is undergoing a change in state from 400 k to 800 k
Answer:
The correct answer is "430 kJ/kg". A further explanation is given below.
Explanation:
The given values are:
T₁ = 400 k
T₂ = 800 k
The average temperature will be:
= [tex]\frac{T_1+T_2}{2}[/tex]
= [tex]\frac{400+800}{2}[/tex]
= [tex]600 \ k[/tex]
From table,
At 600 k the [tex]C p[/tex] will be = 1.075
Now,
⇒ The specific enthalpy = [tex]Cp(T_2-T_1)[/tex]
⇒ [tex]\Delta h=1.075 (800-700)[/tex]
⇒ [tex]=430 \ kJ/kg[/tex]
The process of the body changes that cause a child's body to become capable of reproduction
Answer:
The process is called Puberty.
The dissolution of water in octane (C8H18) is prevented by ________. The dissolution of water in octane (C8H18) is prevented by ________. hydrogen bonding between water molecules ion-dipole attraction between water and octane molecules repulsion between like-charged water and octane molecules dipole-dipole attraction between octane molecules London dispersion forces between octane molecules
Answer:
London dispersion forces between octane molecules
Explanation:
Water is a polar solvent and the molecules of water are held together by hydrogen bonds.
On the other hand octane is a nonpolar molecule held together only by weak dispersion forces.
We know that the interaction of substances depend on the nature of intermolecular forces present in each substance. As a result, water can not interact with octane because octane molecules predominantly have a different kind of intermolecular force between them- the London dispersion forces.
8. Neil pogo sticks from his locker to his science class. He travels 8 m east then 8 m west
back to his locker. What distance did he cover? What was his displacement?
Answer:
12
Explanation:
The distance that Neil Pogo travels is 16 meters. While the displacement is Zero (0).
What is Displacement?Displacement may be defined as the distance traveled by an object from the initial point to the final point. It is a vector quantity and has a direction and magnitude. In a more simple sense, it is known to be the alteration of the position of the object.
According to the question,
The total distance covered by Neil Pogo = 8 m east then 8 m west = 16 meters.
But according to the definition of displacement, his total displacement was zero. This is because the distance between his initial point and the final point is zero.
He returned back to the same place indicating his zero displacements.
Therefore, the distance that Neil Pogo travels is 16 meters. While the displacement is Zero (0).
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Which of the following notations represents an alpha particle?
A. 2 He
C.B+
В. В
D. Y
Answer:
A. 2 He
Explanation:
The notation of an alpha particle is depicted as:
₂He
An alpha particles is a nucleus of 2 protons and 2 neutrons. So it is actually a Helium cation.
Alpha particles are monoenergetic and they mostly have discrete energy.
So, the mass number of the particle is 4 and atomic number is 2
Determine the density (in g/mL) of a substance with a mass of 105 g and a volume of 17.6 mL.
Answer:
Density, d = 5.96 g/mL
Explanation:
Given that,
Mass, m = 105 g
Volume, V = 17.6 mL
We need to find the density of the substance. So,
[tex]d=\dfrac{m}{V}\\\\d=\dfrac{105\ g}{17.6\ mL}\\\\d=5.96\ g/mL[/tex]
So, the density of the substance is 5.96 g/mL.
Describe the motion of a person NOT wearing a seat belt if the car stops suddenly
A the person and car will stop together
B the person will stop faster than the car because they are lighter
C the car will stop and the person will keep moving forward
D the car will stop and the person will speed up
Answer:
c the car will stop and the person will keep moving forward
Explanation:
Because since the person has no force apllied they will keep moving until force is apllied.
A kerosene stove that produces 0.8 g/hr of carbon monoxide (CO) is used in a closed room with a volume of 200 m3. Fresh air enters the room at the rate of 40 m3/hr and stale air leaves at the same rate. Assuming complete mixing and that carbon monoxide is a conservative pollutant (i.e., does not undergo decay), determine the steady state CO concentration
Answer:
20 mg/m3
Explanation:
Given -
S = 0.8 g/hr
Q = 40m3/hr
V =200 m3
As we know, the steady state CO concentration is given by
Css = S/Q
= 0.8/(40m3/hr)
= 800 mg/hr/(40m3/hr)
= 20mg/m3
PLEASE HELP!!!! SCIENCE PROBLEM
indicator, hope this helps :
Answer:
B
Explanation:
Because that's what is being changed into a different color.
Looking at the following equation, which is the correct order of coefficients?
NH3 + O2 --> NO + H2O
Answer: The correct order of coefficients is 4, 5, 4 and 6.
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side.
The balanced chemical equation is:
[tex]4NH_3+5O_2\rightarrow 4NO+6H_2O[/tex]
The correct order of coefficients is 4, 5, 4 and 6.
PLEASE HELP ASAP! GIVING OUT BRAINLIEST PLEASE PLEASE HELP
Name a mixtures of at least 3 items each and how you would separate them. Explain why each of the step would work. Do not use any of the items mentioned in the previous question. (which is salt, sand, water, and iron)
Answer:
That means we do not need to use chemical reactions to separate them. ... The one liquid component in milk is water, and the other is fatty oil. ... Identify the type of substances (solid, liquid or gas) that are mixed in each
Explanation:
Answer:
[tex] \huge \sf \colorbox{pink}{hey \: there}[/tex]
Explanation:
The mixture of clay or sand with water is muddy. The small clay particles become suspended in the water. This kind of mixture is called a suspension. Suspensions are opaque; that means they are cloudy and we cannot see through them very well.
nitrogen atom in NH3 has ___ shared electrons
Answer:
3
Explanation:
nitrogen atom in NH3 has 3 shared electrons.
PLEASE HELPPP!!! Calculate the mass (in grams) of lithium hydroxide that would be needed to produce 8.03 mol of
lithium sulfate in the reaction below.
2 LIOH + H2S04 -> Li2SO4 + 2 H20
Answer:
385g LiOH
Explanation:
Assuming the equation is balanced...
(8.03 mol Li2SO4) x (2 LiOH/ 1 Li2SO4)
= 16.1 mol LiOH ;
16.1 mol LiOH x (24g LiOH/ 1 mole LiOH) = 385g LiOH
The number of moles of LiOH needed to produce 8.03 moles is 16.06 moles. One mole of LiOH weighs, 23 g/mol. Hence, 16.06 moles weighs, 369.3 g.
What is lithium sulphate ?Lithium sulphate is an ionic compound formed by the donation of electron from the lithium metal to the sulphate group. It is formed by the reaction of lithium hydroxide with sulphuric acid.
As per the given balanced chemical equation of the reaction, the 2 moles of lithium hydroxide LiOH gives one mole of lithium sulphate. Then, number of moles of LiOH needed to give 8.03 mol of the product is:
2 × 8.03 = 16.06 mol.
Molar mass of LiOH = 23 g/mol.
mass of 16.06 moles of LiOH = 23 ×16.06 = 369.3 g.
Therefore, the required mass LiOH is 369.3 g.
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Help pls!!!!!!!!!!!!!!!!!!!
Answer:
water
Explanation:
water is made up of both hydrogen and oxygen (h2o)
What is the result of 2.58×0.12, including correct significant figures? Select the correct answer below: 0.3096 0.31 0.310 0.3
Answer:
The answer would depend on the required significant number.
Explanation:
0.3096 is the complete answer
0.31 is the answer when the hundredths place is asked
WORTH 20 POINTS! MY LIFE DEPENDS ON IT HELP
Why do atoms share electrons in covalent bonds?
1. to become ions and attract each other
2. to fill their valence shell
3. to become more polar
4. to increase their atomic numbers
Answer:
2
Explanation:
Covalent bonding occurs when pairs of electrons are shared by atoms. Atoms will covalently bond with other atoms in order to gain more stability, which is gained by forming a full electron shell. By sharing their outer most (valence) electrons, atoms can fill up their outer electron shell and gain stability.
Answer:
To fill their valance shell and become stable!
Explanation:
A solution is prepared by dissolving 25.0 mL ethanol, CH3CH2OH (d=0.789 g/mL), in enough water to produce 250.0 mL solution. What is the molarity of ethanol in the solution?
The molarity = 1.716 M
Further explanationGiven
25 ml ethanol
d = 0.789 g/ml
250 ml solution
Required
The molarity
Solution
Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution
[tex]\large{\boxed {\bold {M ~ = ~ \frac {n} {V}}}[/tex]
mass of ethanol :
= 25 ml x 0.789 g/ml
= 19.725 g
mol ethanol :
= 19.725 g : 46 g/mol
= 0.429
The molarity :
= 0.429 : 0.25 L
= 1.716 M
The molarity of ethanol in the solution is 1.716M
What is the molarity of a solution?Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution
Determine the mass of ethanol :
Mass of ethanol = 25 ml x 0.789 g/ml
Mass of ethanol = 19.725 g
Determine the moles of ethanol
Moles = Mass/Molar mass
Moles = 19.725 g/46 g/mol
Moles of ethanol = 0.429moles
Calculate the molarity using the formula below;
Molarity = Moles/Volume
Molarity = 0.429/0.25 L
Molarity = 1.716 M
Hence the molarity of ethanol in the solution is 1.716M
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How to calculate the orbital period of earth
Answer:
By observing the time between transits, we know the orbital period. Kepler's Third law can be used to determine the orbital radius of the planet if the mass of the orbiting star is known (R3=T2−Mstar/Msun, the radius is in AU and the period is in earth years)
hope this helps you out
What is the main point of paragraph 3?
A Red blood cells
B the skeletal system
C the structure of a bone
D bones, cartilage, and blood vessels
2. The boiling point of a solution containing 6.4 g of the hormone adrenaline in 360 g of
CCl4 is 0.49 K higher than the boiling point of pure CC14. Calculate the molar mass of
adrenaline. (K = 5.02 kg K/mol).
Answer:
MM = 182.13g/mol
Explanation:
Hello!
In this case, since the boiling point elevation is computed via:
[tex]\Delta Tb=i*m*K[/tex]
Thus, since adrenaline is nonionizing, we can compute the molality at first instance:
[tex]m=\frac{\Delta Tb}{i*K}=\frac{0.49K}{1*5.02kg\frac{K}{mol} } \\\\m=0.0976mol/kg[/tex]
Now, we compute the the moles of adrenaline in 360 g (0.360 kg) of CCl4:
[tex]n=0.0976mol/kg*0.360kg\\\\n=0.0351mol[/tex]
Finally, the molar mass:
[tex]MM=\frac{6.4g}{0.0351mol}\\\\MM=182.13g/mol[/tex]
Best regards!
How is the effect of concentration changes on the reaction rate seen in the
rate law?
A. The effect of concentration changes on the rate constant affects
the reaction rate.
O B. A change in concentration of a reactant would change the
exponent of that reactant.
O C. The rate law does not show how concentration changes would
affect the reaction rate.
D. The exponents determine how much concentration changes affect
the reaction rate.
Answer: D. The exponents determine how much concentration changes affect the reaction rate.
Explanation: This is correct. The exponents in the rate law do determine how much the concentration changes impact the reaction rate.
Option A i.e. The effect of concentration changes on the rate constant affects the reaction rate.
what is rate constant?
The proportionality constant, which explains the link between the molar concentration of the reactants and the pace of a chemical reaction, is known as the rate constant. The rate constant, also known as the reaction rate constant or reaction rate coefficient, is indicated by the letter k. Because reactant concentrations decrease as reactants are transformed to products, reaction speeds typically decrease over time. When reactant concentrations are raised, reaction rates generally increase. The temperature has an impact. The following are two methods for calculating rate constant:
Using the Arrhenius formula.The order of the reaction and the molar concentrations of the reactants are used.To know more about rate constant here
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if you start with 4.3 moles of NH3, how many moles of NANH2 can be produced
Explanation:
Mole ratio of NH3 to NaNH2 = 2 : 2.
Moles of NaNH2 produced
= 4.3mol * (2/2) = 4.3mol.
How many grams of H2O are needed to produce 150 g of Mg(OH)2? (Molar mass: H2O = 18.02 g/mol; Mg(OH)2 = 58.33 g/mol )
Answer:
92.6
Explanation:
6 mol x 18.02 g of H2o --> 3 mol x 58.33 g Mg(OH)2
108.12 g of h2o --> 174.99 of Mg(OH)2
g of H2O is 150 g of Mg(OH)2
150g x 108.12g / 174.99 =
92.67
What is made when a salt is dissolved in water?
Answer:
water
Explanation:
the salt dissapears and turns
into vapor
Answer:
A solution is made when a solid (which we call a solute) dissolves into a liquid (that we call the solvent) one example of a solution is salt dissolved in water. The salt and water can be separated again by evaporation (the water will evaporate if left in a got place leaving the salt behind. I don't know if that was the answer that you were looking for
11) How many moles of CO2 can be produced from
5.0 moles of O2?
Answer:
3.6 moles
Explanation:
5.0moles produce 44g/x will produce 32g the answer is a3.6moles